Carburetor



A. COLEMAN Aug. 2, 1932.

CARBURETOR Filed Oct. 31, 1930 .INVEN TOR.

A TT ORNE Y.

Patented Aug. 2 1932 I I i I p UNITED STATES PATENT OFFICE Application filed October 31, 1930. Serial No. 492,465.

My invention relates to carburetors, and controlled by a float mechanism of any premore particularly to those of the heater type fez-red construction, as it forms no part of wherein the fuel is vaporized by exhaust the present invention. The fuel is disgases from the engine supplied by the carcharged from the float chamber through a 6 buretor, the principal object of the invenneck 6 connecting the chamber with a T- 50 tlon being to control the fuel flow and its shaped fitting 7 having vertical connections rate of vaporization in proportion to the fuel 8 and '9 and a horizontal connection 10, the dem nd of th i connection 10 being connected by a pipe 11 Another object of the invention is to apply communicating with the bore 12 in the fuel 1 the heat in such a manner as to provide for Outlet member 4 at a point above the throttle 55 substantially instant vaporization of the fuel 13, (hereinafter described), to permit idling directly on its admission to the mixing chamof the motor when the throttle is in closed her of the carburetor. position.

Other important objects of the invention The upper connection 8 is locatedin axial 1 are to prevent clogging of the fuel jet and alignment with the mixing chamber 3 and 00 to provide an initial air vapor mixture, and connected therewith is a tube 14 or jet threadpositive injection of the mixture into the ed into the bottom Wall 15 of the mixing major air supply. chamber, and through which the major por- In accomplishing these and other objects tion of the fuel is admitted into the carof the invention, I have provided improved buretor. 65

details of structure, the preferred form of Formed integrally with the bottom wall which is illustrated in the accompanying of the mixing chamber is a heater chamber drawing, wherein: p 16 havin a heat inlet 17 adapted to be conig. l is a perspective sectional view nected wlth the exhaust pipe of an internal through a carburetor constructed in accordcombustion engine for supplying hcatingme- 70 ance with my invention. dium to the chamber 16, and having an out- Fig. 2 is an enlarged fragmentary sectionlet connection 18 through which the exhaust al view through the fuel jet, particularly ilgases are adapted to be returned to the exlustrating the needle for controlling effective haust pipe. 0 port area of the jet. Formed in the heater chamber in axial 7 Fig. 3 is a horizontal sectional view alignment with the tube 14 is an annular wall through the heater chamber for vaporizing 19 aving an inner diameter larger than the the fuel passing through the carburetor. diameter of the tube 14 to provide an annular Fig. 4 is a detail perspective View of the air space 20 surrounding the tube 14 to prelower end of the et needle and the jet vent gasifying of the fuel in the tube, which 8 through which fuel is admitted to the mix- I have found from actual experiments seriing chamber of the carburetor. ously interferes with the action of the car- Referring more in detail to the drawing: uretor.

1 designates a carburetor casing including I have therefore provided for applying the a fuel outlet connection 4 adapted to be conmixing chamber, which heat is transferred nected to the intake manifold of an internal by conduction through the bottom'wall and combustion engine. is localized about the zone of the fuel jet as Fuel is admitted to the float chamber now described.

a float chamber 2, a mixing chamber 3, and heat to the fuel during its admission to the through an inlet connection 5, the flow being The fuel jet preferably comprises a nipple 41 so that when 21 threaded into the bottom wall of the mixing chamber and provided with a port 22 of sufficient diameter to pass fuel necessary to maintain the engine at its maximum speed. Su ported on the wall 15 of the mixing chamber in concentric alignment with the jet and extending upwardly therefrom is a tube or nozzle 23 having laterally extending feet 24 and 25 at its lower end through which fastening devices 26 are extended to secure it to the bottom of he mixing chamber. The tube or nozzle 21. is of suihcient length to project within the lowerend of a Venturi member 27 and its lower end is provlded with airinlct ports 28 through which air is drawn for initially mixing with the vapor fuel emitted from the jet by siphoning action of the major air supply passing through the yenturi 23. The major air supply is admitted to the mixing chamber through a tubular inlet 29 forming an integral part of the earburetor housin and is controlled by a butterfly valve 30 xed to a shaft 31 rotatably mounted in the member 29 in response to an actuating lever 32 which may be controlled in any suitable manner.

The throttle valve 13 previously mentioned is fixed to a shaft 33 pivotally mounted in the member tand is actuated by a lever 34 exteriorly of the carburetor.

In order to control vaporization and amount of fuel passing through the jet, I provide a longitudinally reciprocable adjusting needle 35 having an offset upper end 36 terminating in a hook 37 which is connected to an ear 38 projecting from the face of valve 13, so that when the lever 34 is actuated to move the throttle valve 13 a pointed end 39 on the needle will move through the jet port to control its effective port area, that is, when the valve 13 is in open position, the maximum amount of fuel is admitted through the jet, and when the valve 13 is moved to closed position the needle tends to close the port to reduce the amount of fuel passing therethrough.

As above pointed out, the heat supplied is centered around the nozzle and top of the jet so that the fuel is vaporized during its passage therethrough. Attention is also directed to the fact that the shape of the adjusting needle spreads the fuel outwardly in thin sheet form into contact with the heated surface, and that the hot needle extending into the cent-er of the flow aids in the vaporization. 1

It is also apparent that when the throttle valve 13 is actuated, the needle is reciprocated through the jet to prevent foreign matter and carbon from stopping the flow.

In order to provide for quick acceleration of the engine, I provide a pump 40 supported on the side wall of the mixing chamber and having its lower end connected by a conduit the piston 43, which is operably connected with the throttle lever by a link 44, is moved downwardly, the fuel trapped in the piston cylinder is discharged through a nipple 45 communicating with the interior of the mixing chamber slightly above its bottom 15. The fuel being discharged onto the hot surface is quickly vaporized and drawn through the ports 28 to supplement the fuel supplied by the jet.

What I claim and desire to secure by ters Patent is:

1. In a carburetor including a casing having a mixing chamber provided with a fuel outlet, a vertical tube within said chamber and carried by the bottom thereof, a jet havin a port for admittin" fuel through the tu e to the mixing cham er, means for supplying fuel to thejet, a chamber in said casmg below the mixing chamber for heating the jet and tube to vaporize fuel passing therethrough, and a valve controlling the outlet from the mixing chamber.

2. In a carburetor including a casing having a mixing chamber provided with a fuel outlet, a heating chamberbelow said mixing chamber for heating the same, a fuel supply pipe for admitting fuel to the mixing chamber, said fuel supply pipe adapted to be heated at its upper end by conduction from said heating chamber so as to vaporize fuel passing therethrough, a valve controlling the outlet in the mixing chamber, and a needle valve associated with the fuel supply pipe and operably connected with the first named valve for controlling fuel passing through the fuel supply pipe.

3. In a carburetor including a casing having a mixing chamber provided with an outlet, a heater below and forming the bottom of the mixing chamber, a tube mounted on the heater and extending into the mixing chamber and heated by conduction of heat from the heater to vaporize fuel passing therethrough, a jet for supplying fuel to the tube extending through the heating chamber, there air space between the major portion of the jet and heater for insulating the tube from the heating effect of the heater and prevent vaporization of fuel in the jet.

4:. In a carburetor including a casing having a mixing chamber provided with a fuel outlet, a valve controlling the outlet, a fuel jet in the mixing chamber, means for admitting fuel to the jet, a nozzle surrounding the jet and having air ports for admitting air to provide an initial air and fuel mixture, means for heating the nozzle and jet by conduction from a source of heat, said source of heat also heating the air passing through the air ports thereby vaporizing the fuel, and means controlling passage of fuel through the jet operable in synchronism with the valve controlling the outlet.-

5. In a carburetor including a casing having a mixing hamber provided with a fuel Tactbeing an outlet and an air inlet, a venturi associated with the outlet of the mixing chamber, a fuel jet in the mixing chamber, a nozzle havin parts in its lower end associated with the jet and extending Within the Venturi, a heating chamber below the mixing chamber for heating the same and the nozzle and jet to vaporize fuel passing from the jet through the tube, Valves for controlling said fuel outlet and air inlet, and means for operating said valves independently of each other.

In testimony whereof I aflix my signature.

ARTHUR COLEMAN. 

